1. Field of the Invention
The present invention relates to adjustable sprinklers used for irrigation and, more particularly, to adjustable sprinklers for precision irrigation which use a mechanically preprogrammed disk for changing water flow within the sprinkler to attain precision irrigation.
2. Related Art
There are various types of sprinklers used for irrigating gardens, farms, lawns, or the like. Some such sprinklers utilize a rotating element which is spring-loaded and reacts to water emitting from a nozzle by bouncing away from the stream of water, thereby causing a counter weight to rotate the nozzle. This process is repeated such that the nozzle rotates in a 360.degree. pattern and irrigation of a substantially round area of land is obtained.
These rotating sprinklers may be adjusted to rotate through only an arc and thereby irrigate only a sector of circle.
Although such rotating sprinklers have partial adjustability, they are very limited as to the shapes of the areas for which they can achieve precision irrigation. Indeed, these rotating sprinklers can only be programmed to irrigate a circular region or sector of a circular region.
Unfortunately, these prior art rotating sprinklers waste a large amount of water when used to irrigate non-circular areas due to over-spraying the non-circular areas. This is a particularly undesirable result in regions suffering from drought.
Further, over-spraying may inconvenience pedestrians attempting to walk in the area over-sprayed. Indeed, when land owners are irrigating lawns or the like, nearby sidewalks may be subject to over-spray from a rotating sprinkler. Pedestrians attempting to traverse a wet area of a sidewalk (or other area) may be inadvertently drenched with water or may slip and fall on slippery surfaces caused by the over-spray. Further, such pedestrians may be at risk from being hit by passing automobiles if they attempt to leave the sidewalk and walk along the street to avoid the over-spray.
Further, over-spray may also interfere with nearby electric lines causing shock hazards to passers by and/or users of the sprinkler.
Accordingly, there is a need in the art for an automatic adjustable sprinkler for precision irrigation which can cover areas of many different shapes without over-spray.